I find it funny that the day after MadGamer asked about that MS has released the preview for us
I tried it earlier.
Sky listings and basic control work well, apart from the clutter caused by the radio stations.
I tried using SmartGlass and managed to do Live Pause etc. Couldn't get to the Planner, though, despite the video on the Xbox Wire article saying you can access recorded content. Coming later, or just box dependent?